Noncontact support platforms are useful in processes that require supporting and transporting of thin, and typically fragile, workpieces, where contact of the workpiece with solid surfaces is to be avoided. For example, a thin workpiece may include a thin pane of glass, e.g., for incorporation into a display screen, or another thin material. The process may include application of a substance or tool to the workpiece, or inspection of the workpiece.
A typical noncontact support platform includes a table whose horizontal top surface is made to be extremely flat. The table top includes an arrangement of openings. Some of the openings (e.g., approximately half of the openings) are pressure openings out of which air is blown to form an air cushion on which the workpiece may be supported above the table top. The remaining openings are air return openings through which air may flow from the air cushion and into the table.
When precise control of the distance between the workpiece and the table top is not required, the air return openings may open to atmospheric pressure. However, where the distance between the workpiece and the table top is to be controlled precisely, vacuum may be applied to the air return openings. Uniformity of the distribution of the various air openings over the table top may contribute to precision the height of the workpiece. In addition, such uniformity may also enable uniform convective heat transfer throughout the workpiece, thus facilitating a uniform temperature at all parts of the workpiece.